Method for the accelerated dialytic recovery of foreign substances from passive collectors consisting of semipermeable membranes having different dimensions

Abstract

The invention relates to a dialysis method of recovering foreign substances, particularly low-molecular weight inorganic and/or organic substances, from semipermeable membrane of varying length and dimensions, using a PLE (pressurized liquid extraction) apparatus. The membranes are preferably in the form of a tube, for example semipermeable membrane devices (SPMDs) which, in the form of passive samplers, accumulate foreign substances/pollutants on an absorbent or adsorbent.

1. A method for the dialytic recovery of a foreign substance from a passive sampler, comprising
 performing dialysis with a solvent or a mixture of solvents with a pressurized liquid extraction apparatus, 
 which apparatus comprises an extraction cartridge in which a semipermeable passive sampler loaded with a foreign substance is fixed in a netlike mask of an inert material, 
 wherein the semipermeable passive sampler comprises semipermeable membranes of varying lengths and dimensions. 
 
     
     
       2. The method according to  claim 1 , wherein the passive sampler is tubular in shape and includes at least one hydrophobic absorbent or adsorbent of high accumulative capacity for semivolatile organic pollutants. 
     
     
       3. The method according to  claim 2 , wherein the absorbent or adsorbent of high accumulative capacity is triolein, Lichrolut, XAD, Tenax, silicone, and/or active carbon. 
     
     
       4. The method according to  claim 2 , wherein the absorbent or adsorbent of high accumulative capacity is triolein. 
     
     
       5. The method according to  claim 2 , wherein the absorbent or adsorbent of high accumulative capacity is silicone and/or active carbon. 
     
     
       6. The method according to  claim 2 , wherein the absorbent or adsorbent of high accumulative capacity is a copolymer, polymer or resin. 
     
     
       7. The method according to  claim 1 , wherein the netlike mask consists of metal or ceramics. 
     
     
       8. The method according to  claim 1 , wherein the dialysis is carried out at a pressure in the pressurized liquid extraction apparatus which is higher than atmospheric pressure. 
     
     
       9. The method according to  claim 1 , wherein the temperature is 60°C. at maximum. 
     
     
       10. The method according to  claim 1 , wherein the solvent is n-hexane, toluene, a mixture of cyclohexane and ethyl acetate, a mixture of cyclohexane and acetone, a mixture of n-hexane and methylene chloride, a mixture of n-hexane and dichloromethane, or a mixture of n-hexane and acetone. 
     
     
       11. The method according to  claim 10 , wherein a solvent mixture of n-hexane and acetone at a ratio between 90:10 and up to 50:50 is used in the dialysis of semivolatile to low volatile organic pollutants. 
     
     
       12. The method according to  claim 1 , wherein semivolatile to low volatile organics are dialyzed for at least 4×10 minutes. 
     
     
       13. The method according to  claim 1 , wherein the foreign substance is a pollutant from environmental monitoring or from medical, biochemical or biological sector. 
     
     
       14. The method according to  claim 1  wherein the foreign substance is sediment, soil, old waste, or vegetable matrix. 
     
     
       15. The method according to  claim 1 , wherein the dialysis is carried out at a pressure of 3.5 Mpa in the pressurized liquid extraction apparatus. 
     
     
       16. The method according to  claim 1 , wherein the temperature is between room temperature (20°C.) and 50°C. 
     
     
       17. The method according to  claim 1 , wherein the temperature is at room temperature (20°C.). 
     
     
       18. The method according to  claim 1 , wherein the foreign substance is a low-molecular weight pollutant. 
     
     
       19. The method according to  claim 1 , wherein the semipermeable passive sampler consists of semipermeable membranes of varying lengths and dimensions. 
     
     
       20. The method according to  claim 1 , wherein the netlike mask comprises a metal or ceramic matrial. 
     
     
       21. The method according to  claim 1 , wherein the netlike mask is made of stainless steel.